gilliland



UNITED STATES PATENT OFFICE.

EZRA T. GILLILAND, OF EosToN, MASSACHUSETTS, ASSIGNOR To THE AMERICANBELL TELEPHONE COMPANY, OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 384,201, dated June 5,1888.

Application filed September 1!), 189.5. Serial No. 177,595. (No model.)Patented in Belgium January 27, 1886, No. 71,172, and

, in England January 19, 1886, No. 1,310.

To all whom it may concern.-

Be it known that I, EZRA T. GILLILAND, residing'at Boston, in the countyof Suffolk and State of Massachusetts, have invented certainImprovements in Telephone Trans mitters, (patented in England, No.1,310, Jannary 29, 1886, and in Belgium, No. 71,772, January 27, 1886,)of which the following is a specification.

The present invention relates more parlicularly to the construction ofbattery telephones or transmitters of that class which employ as thecurrent-varying medium a mass of mobile material-such as finelydividedcarbon rcsting upon a horizontal diaphragm; and it consists insupporting such transmitter upon a vertically-swinging arm provided withmeans whereby as the free end of the arm is raised or lowered thetelephone is so turned upon its support that in any position ofsaid armthe diaphragm remains horizontal. The invention also includes certainparticular arrangements and combinations of parts as hereinafter fullyset forth. C

Figure 1 is a longitudinal cross section of the transmitter and itssupport-ingarm. Fig.

2 isa cross-section on line :4 2, Fig. 1. Fig. 3 1s a cross-section online 00 m, Fig. 1. Fig. 4

is a cross-section at y Fig. 1. top plan view complete.

Ois a metal casting, the upper section being cup-shaped to receive thetransmitter T. The section t forms a passage or tube which incrosssection resembles an ellipse, Fig. 2. This terminates in amouth-piece, m. The wall oft opposite the speaker or most remote isnearly flat, approximating to a plane surface. 7' is a projectionintegral with casting O and calculated to form ajoint.

The transmitter proper, T, is composed of a ring of insulating material,I), threaded upon the exterior. The upper edge is countersunk to receivethe rim of the electrode e, which is immersed in a finely-dividedconductingma 5 terial, as carbon. The electrode 6 is of brass platedwith gold, so that foreign matter in the carbon cannot corrode 0roxidizeit. The cap a has a rim screw-threaded on both outside and insidesurfaces. This screws down upon Fig. 5 is a ring I and holds electrode 6firmly in position. A centrallypcrforated ring, 0, has a screw-threadedrim, and when the thin sheet of platinum forming the diaphragm dis inposition it is screwed down upon insulating-ring b and holds thediaphragm in position. An airspace or vocalizing-cha'mber is provided byturning a shoulder upon the interior of ring 0, as shown in thedrawings. The electrode e is connected with the battery through cap aand the adjustable arm A. The diaphragm is the complementary electrode,and for the purpose of connecting it with the induction-coil and batterya circular plate of brass, 0, fitting the cup 0, is insulated upon itsunder side by an insulating-busl1iug, i, and is placed in the bottom ofcup 0. The screwpost q is electrically connected to plate 0. Diaphragm(I, when the transmitter T is screwed into position in cup 0, makesContact with plate 0. From post q an insulated con- 79 ductor, n, iscarried to a screw-post, as 4, with which the primary of coil I isconnected.

D is a east-metal box, which may be Screwed to the wall. The requisitenumber of insulated screw-posts, 8 5 7 9, are placed in the wall of boxD. The inner ends of these screw-posts are headed, and theinduction-coil I, fixed to the back-board, 10, has the terminals of itstwo coils connected to springs or projections, as 1 2, which register orcoincide with the insulated .screwposts. By this arrangement ofconnections I am enabled to readil y change or substitute one coil foranotheigand this improved feature-that of the interchangeability ofparts-4s applied tothc other elementary parts of the telephone.

The adjustable arm A is composed of two sections, A and A, as shown inFigs. 1, 4, and 5. These two sections embrace the projection S, and arepivoted thereto by pivot P. The two sections A A are also screwedtogether. The free end of the arm embraces projection j of thetransmitter-frame, and a pivot, p, re tains the transmitter in a movableposition. A metal bar, 13, is pivoted to the support S at g and to theframe of the transmitter T at f. Now as the transmitter is raised orlowered to vary its distance from any stationary object the bar B holdsthe transmitter T in its initial position, as with its diaphragm in ahorizontal position. This automatic adjustment of the relative positionof the transmitter prevents the displacement and disarrangement of themass of finely-divided conducting material forming the contact-varyingmedium, and prevents any disturbance of the normal adjustment. The samearrangement would be applicable to retain any other relative posit-ionin which it mightbe found desirable to set the instrument. The spring 3and link Z act as a counter-weight and counteract the tendency of thearm to drop.

The operation of thetransmitter is similar to others of its class.

I make no claim to the specific form of electrode e, as that is theinvention of others.

\Vhat I claim, and desire to secure by Let ters Patent, is

1. The combination of a telephonetransmitter, a hollow arm pivoted tosaid transmitter and to a fixed support, and a rigid bar enclosed insaid hollow arm and pivoted at one end to said transmitter and at theother to said support, substantially as described.

2. A. telephone-transmitter having a fixed horizontal diaphragm uponwhich the currentvarying medium rests, a downwardly-projecting tube orpassage through which the soundwaves are directed upon the diaphragm,combined with a hinged arm, upon the free end of which the transmitteris pivoted, and a mechanical connection between the transmitter and afixed support whereby the movement of the transmitter to vary itsdistance from a fixed point automatically turns the transmitter upon itspiy'ot, so as to keep the diaphragm always in a horizontal position,substantially as described.

3. The combination, with a telephone con taining a body of mobilematerial, of a vertically-swinging arm upon which said telephone ismounted, and means for maintaining said telephone in a horizontalposition as the arm is swung up and down, substantially as set forth. I4. The combination, with a telephone containing a body of mobilematerial, such as finely-divided carbon particles, constituting thecurrent-varying medium, of a verticallyswinging arm upon which saidtelephone is mounted, and means for maintaining said telephone in ahorizontal position as the arm is swung up and down, substantially as described.

In testimony whereofl have signed my name to this specification, in thepresence of two subscribing witnesses, this 17th day of September, 1885.

EZRA T. GILLILAND.

Witnesses:

WM. B. VANsIzn, V. M. BERTHOLD.

